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u'NtV.  OF  FL  LIB 
DOCUMENTS  DEPT 


U.S.  DEPOSITORY 


A.  1. 19. 


U.  S.  DEPARTMENT  OF  AGRICULTURE, 

BUREAU  OF  ANIMAL  INDUSTRY. 

DAIRY  DIVISION. 


THE  MANUFACTURE  OF  COTTAGE  CHEESE  IN  CREAMERIES 
AND  MILK  PLANTS. 

Cottage  cheese,  properly  made,  offers  a  most  palatable  and  nutri- 
tious article  of  food  at  a  relatively  low  price  compared  to  the  cost 
an'fi  nutritive  value  of  many  other  protein  foods.  The  simple 
method  of  manufacture  recommends  its  adoption  by  creameries  and 
milk  plants  which  desire  to  dispose  of  skim  milk  to  good  advantage. 

Since  the  quality  of  cottage  cheese  is  judged  by  flavor  and  texture, 
it  is  very  important  that  the  skim  milk  used  be  of  good  clean  flavor 
and  free  from  foreign  odors.  It  is  possible  for  the  maker  to  control 
the  texture  of  the  cheese,  but  if  the  flavor  also  is  to  be  controlled, 
good  raw  material  is  necessary. 

PASTEURIZATION  OF  SKIM  MILK  IMPORTANT. 

The  fresh  skim  milk  from  the  separator  should  be  pasteurized  and 
the  process  of  manufacture  begun  as  soon  as  possible  thereafter,  in 
order  that  the  fermentation  or  souring  process  may  be  controlled 
to  the  best  advantage.  Perhaps  the  largest  part  of  the  cottage 
cheese  used  is  made  from  raw  skim  milk,  but  the  advantages  to  bo 
derived  from  proper  pasteurization  are  so  great  as  to  make  it  highly 
advisable  to  adopt  this  system  of  manufacture.  Pasteurization 
adds  but  little  extra  expense  to  the  cost  of  making  and  has  the 
following  important  points  in  its  favor: 

1.  It  gives  a  sanitary,  safe  food  product  free  from  all  danger  of 
disease-producing  bacteria. 

2.  It  allows  the  use  of  a  pure-culture  starter  to  control  the  forma- 
tion of  the  mild-acid  curd,  giving  the  characteristic  sour-milk  flavor 
so  much  desired. 

Pasteurization  requires  but  little  additional  work,  provided  suit- 
able equipment  is  at  hand.  A  temperature  of  145°  F.,  held  for  30 
minutes,  gives  ah  efficient  pasteurization  and  does  not  affect  the 
coagulability  of  the  milk  for  making  cottage  cheese.  The  use  of  a 
starter,  however,  is  necessary  in  order  to  obtain  the  desired  flavor. 

101977°— 17 


EQUIPMENT  REQUIRED. 

The  extra   equipment   necessary  in   the  manufacture  of  cottage 

cheese  depends  upon  the  apparatus  on  hand  and  whether  the  skim 

milk  is  to  be  pasteurized.     If  pasteurization  is  to  be  included  in  the 

,  process  the  following  apparatus  is  needed  for  making  cottage  cheese : 

1.  Pasteurizing  outfit. 

2.  Cheese  vat. 

3.  Drain  rack. 

4.  Drain  cloths. 

5.  Curd  IvniveS;  curd  pail,  and  vat  whey  strainer. 

METHOD  OF  MANUFACTURE. 

RIPENING  THE  SKIM  MILK. 

The  object  of  ripening  is  to  obtain  the  characteristic,  mild,  sour- 
milk  flavor  and  at  the  same  time  develop  the  required  degree  of 
acidity  to  cause  a  separation  of  the  curd  when  the  curdled  milk  is 
heated.  The  temperature  used  for  ripening  depends  upon  the 
quantity  of  starter  added  and  how  soon  a  firm  coagulation  is  desired. 
The  greater  the  quantity  of  starter  and  the  higher  the  temperature 
the  sooner  the  milk  will  curdle.  A  temperature  above  75°  F.,  how- 
ever, is  not  desirable;  usually  60°  or  70°  F.  produces  best  results. 
Experience  will  show  the  right  combination  of  starter  and  temperature 
to  be  used  for  best  results  under  existing  conditions.  Raw  milk 
allowed  to  sour  naturally  usually  develops  a  weU-flavored  curd,  but 
the  chances  of  obtaining  a  fine-fiavored  product  regularly  are  greatly 
increased  by  pasteurization  and  the  use  of  a  good  starter.  In  case 
the  starter  is  of  poor  quality  it  should  not  be  used  but  natural  souring 
should  be  depended  upon  instead.  It  is  desired  to  separate  the  curd 
from  the  whey  shortly  after  the  milk  shows  a  firm  and  smooth 
coagulation.  At  this  stage  sufficient  acid  is  present  to  give  a  good, 
clear  separation  of  the  whey. 

CUTTING  AND  HEATING  THE  CURD. 

The  best  method  of  cutting  the  curd  is  to  use  regular  cheese-curd 
knives.  They  give  fairly  uniform  cubes  of  curd  from  which  the  whey 
can  be  expelled  with  small  loss  of  fuiely  broken  curd  passing  through 
the  drain  cloth.  To  break  the  coagulated  milk  with  a  mechanical 
stirrer  produces  too  many  fine  particles  of  curd  which  may  be  lost 
during  drainage.  Steam  is  turned  on  when  the  curd  is  cut,  and  the 
temperature  is  raised  gradually.  At  frequent  intervals  the  coagulum 
is  gently  stirred  to  insure  a  uniform  temperature  and  to  prevent 
undue  cooking  of  the  curd  along  the  sides  and  bottom  of  the  vat. 
The  proper  temperature  required  to  give  a  good,  clear  separation  can 
be  readily  ascertained  by  examination  of  the  mixture  in  the  vat.  At 
this  stage  the  whey  should  be  clear  or  show  very  little  cloudiness. 


'4* 


The  texture  of  the  cheese  is  controlled  by  temperature  and  time  of 
heating  the  coagulum,  and  the  extent  to  which  the  curd  is  drained. 
Considerable  variation  with  regard  to  the  temperature  of  heating  and 
the  time  the  curd  is  allowed  to  drain  is  therefore  necessary.  A  tem- 
perature of  from  90°  to  105°  F.  gives  the  desired  results  for  all  normal 
conditions,  and  it  is  rarely  necessary  to  exceed  100°  F.  Heating  the 
coagulum  to  a  higher  temperature  favors  the  more  rapid  expulsion 
of  whey  from  the  curd  and  produces  a  dry,  coarse-grained  cheese 
demanded  by  some  markets.  Continued  heating  at  the  temperature 
giving  a  clear  separation  of  the  curd  and  w^hey  hastens  the  removal  of 
whey  and  shortens  the  time  of  drainage.  For  making  a  smooth, 
uniform-textured  cheese  care  must  be  taken  not  to  heat  the  curd  too 
long,  especially  at  a  high  temperature,  as  such  conditions  tend  to  pro- 
duce a  dry,  coarse-bodied  cheese.  A  smooth,  uniform-textured 
cheese  brings  out  the  fine  flavor  to  the  best  advantage,  as  it  has  none 
of  the  harshness  or  grittiness  fomid  in  the  dry,  coarse-grained  product. 
The  use  of  a  high  temperature  shortens  the  time  required  for  making, 
but  much  greater  attention  is  necessary. 

DRAINING  THE  CURD. 

After  the  curd  has  been  heated  for  from  20  minutes  to  an  hour,  de- 
pending upon  conditions,  the  whey  may  be  drawn  from  the  bottom 
of  the  vat  into  the  cloth-lined  drain  rack.  The  greater  portion  of  the 
whey  is  drawn  off  through  the  vat  whey  strainer  and  passes  quickly 
through  the  drain  cloth.  The  mixture  of  curd  and  w^hey  remaining 
is  then  placed  in  the  drain  rack,  where  draijiage  is  completed.  An 
occasional  raising  and  lowering  of  the  drain  cloth  hastens  drainage- 
The  extent  of  drainage  depends  upon  the  texture  of  cheese  desired, 
the  temperature  and  the  length  of  time  of  heating.  When  a  fairly 
low  temperature  is  used,  drainage  can  be  readily  controlled.  It  must 
continue  until  there  is  no  accumulation  of  free  whey  in  the  finished 
cheese.  A  high  temperature  tends  to  give  more  free  whey  in  the  fin- 
ished product,  unless  the  curd  is  allowed  to  drain  to  such  an  extent 
that  the  yield  is  materially  reduced;  this  also  increases  the  proba- 
bility of  producing  too  dry  a  cheese.  In  case  the  curd  is  draining  to 
an  extent  that  the  cheese  will  be  too  dry,  it  can  be  checked  by  wash- 
ing with  cold  w^ater. 

SALTING. 

Salt  is  sprinkled  uniformly  over  the  curd  and  well  worked  in  with  a 
paddle.  The  rate  of  salting  depends  upon  the  market  demands.  One 
and  one-quarter  pounds  to  100  pounds  of  curd  gives  a  medium-light 
salted  cheese  which  is  desired  by  most  consumers.  Light  salting 
gives  the  consumers  more  opportunity  to  prepare  the  cheese  to  suit 
their  individual  tastes. 

The  addition  of  1  pound  of  sweet  cream  to  10  of  curd  adds  greatly 
to  the  palatability  of  the  cheese.'  The  cream  can  be  worked  into  the 
curd  together  with  the  salt. 


UNIVERSITY  OF  FLORIDA 

lllllllllllllllllillllllll 

*  3  1262  08925  9450 

PACKING  AND  MARKETING. 

The  ideal  method  of  marketing  is  in  the  sanitary,  single-service, 
paraffined  paper  containers,  which  are  convenient  for  the  dealer  to 
handle  and  are  attractive  to  the  buyer.  Cheese  shipped  in  bulk 
may  be  packed  in  butter  tubs  or  in  ordinary  milk-shipping  cans. 
To  insure  marketing  in  the  best  condition,  the  cheese,  immediately 
after  it  is  made,  should  be  placed  in  the  refrigerator  and  held  at  low 
temperature  until  marketed.  Fresh-made  cottage  cheese  should  not 
be  shipped  until  after  it  has  been  well  cooled,  for  w^arm  cheese  favors 
the  quick  development  of  fermentation  and  deterioration  in  quality. 

YIELD  OF   CHEESE. 

The  yield  of  cheese  varies  from  12  to  22  poimds  per  100  pounds  of 
milk  and  depends  almost  entirely  upon  the  amount  of  moisture  left 
in  the  curd,  which  in  turn  is  controlled  by  the  method  of  manufac- 
ture. The  factors  which  influence  the  percentage  of  moisture  in  the 
curd  and  determine  the  yield  are — 

1.  Temperature  and  length  of  time  of  heating  curdled  milk. 

2.  Extent  of  drainage. 

3.  Condition  of  milk. 

The  moisture  in  the  curd  can  be  fairly  well  controlled  by  the 
extent  of  drainage,  provided  too  high  a  temperature  has  not  been 
used  for  heating  and  the  time  of  heating  has  not  been  excessive. 
The  physical  condition  of  the  milk  often  has  a  marked  influence  upon 
the  resulting  yield.  A  weak,  unevenly  coagulated  curd,  when  cut, 
makes  a  large  quantity  of  fine  curd,  much  of  which  may  be  lost  in 
drainage. 

An  ideal  quality  of  cheese,  which  brings  out  the  delicate,  mild 
flavor  to  the  best  advantage,  is  rather  firm,  smooth,  and  yields  from 
15  to  20  pounds  to  100  pounds  of  milk. 


WASHINGTON  :  GOVERNMENT  PRINTING  OFFICE  :  1917 


